I hesitate to write this, but it seems that face-blindness could be related to autism spectrum. I know someone who is diagnosed on the spectrum and has face blindness and feels the social anxiety of it in much the same way as the author. Also, the author describes several behaviors that are on the spectrum.

I also noticed that many of the anxieties described by the author were projected and not materialized. She was afraid of how people would react and how she would feel in awkward situations, but when it finally happened and she admitted her condition, it went fine. Shyness and social anxiety have an element of self-fulfilling prophecy.